1. Field of the Invention
This invention relates to a facility for combining and amplifying two broadband signals as set forth in the preamble of claim 1.
2. Description of the Related Art
DE 44 36 818 discloses a facility for combining and amplifying two broadband signals. One of the broadband signals contains analog cable television signals which are transmitted in a coaxial cable network. The other broadband signal contains digital bidirectional signals which are transmitted in a fiber optic network that is to be installed in addition to the existing coaxial cable network. In the facility, the received cable television signals are amplified in a unidirectional amplifier; the received digital bidirectional signals are converted from optical to electrical form and are then amplified in a bidirectional amplifier. The amplified cable television signals and the amplified bidirectional signals are then combined by means of a coupling device. Cable television signals and bidirectional signals are transmitted in different frequency bands, so that the coupling device can be implemented with frequency-selective circuits. Two amplifiers are thus necessary in the facility, which together have high power dissipation. The facility is remotely fed over the existing cable television network with power limited in value, so that a power dissipation increased by the additional bidirectional amplifier is disadvantageous and may require a new remote power feeding concept.
DE 195 05 578 discloses an optical transmission system for transmitting cable television signals as well as video and telecommunications signals. The cable television signals are transmitted in a first optical transmission network from a center to a network termination. The video and telecommunications signals are transmitted from the center to the network termination in a second optical transmission network. In the network termination, the cable television signals and the video signals, after being separately converted from optical to electrical form, are fed unattenuated to a broadband amplifier and are amplified together. The telecommunications signals are first converted from optical to electrical form together with the video signals, then separated from the video signals, attenuated, and amplified in a narrow-band amplifier. Cable television signals, video signals, and telecommunications signals are transmitted in different frequency bands. The joint amplification of cable television signals and video signals saves one amplifier, but the two signals come from different networks, which may result in mutual interference when the signals are combined.